The present invention is drawn to a device for measuring the velocity of a fluid flowing in a flow channel of a conduit.
Devices as aforesaid are known in the art under the name of Karman eddy counters. These devices have a element for disturbing fluid flow located in the flow channel of a conduit for generating eddies. The eddies cause pressure fluctuations in the frequency which are proportional to the rate of flow of the fluid in the flow channel. The pressure fluctuations generate charge differences which can be sensed by a piezoelement which sense conditions which are then evaluated and converted into voltage signals indicating flow measurement.
U.S. Pat. No. 5,109,703 discloses a Karman eddy flow meter of the type discussed above. The device comprises an eddy generating element in the form of a fluid flow disturbing body. Fluid pressure protecting openings are connected to a pressure sensor via a plurality of channels. A problem associated with the device of the '703 patent is the plugging of the channels which adversely affects the condition sensed by the pressure sensor. In addition to the foregoing, the insertion of the eddy generating element (the disturbing body) into the tubular mold part in combination with the location of the pressure sensor partially outside of the molded space results in a sealing problem in the unit.
It is the principle object of the present invention to create a device for measuring the velocity of fluid flow in a flow channel of a conduit employing a Karman eddy device which is of simple construction, easily mounted within the conduit without sealing problems, and which operates reliably and accurately over a wide range of flow velocities.
Further objects and advantages of the present invention will appear hereinbelow.